This invention relates generally to the art of medical ultrasound devices, and more specifically concerns the ultrasound imaging of the bladder.
A critical function of the human bladder is the elimination of urine from the bladder at various times, referred to generally as voiding. Dysfunctions of the bladder involving the voiding process include an inability to completely empty the bladder, as well as various forms of incontinence, such as stress incontinence, stress urge overflow and nocturnal incontinence. Various clinical tests have been developed and used to diagnose specific bladder dysfunction. One commonly used test involves the measurement of the volume of urine that exits from the urethra using what is known as a uroflow machine. A xe2x80x9cpulsingxe2x80x9d flow as opposed to a smooth rise and then fall in flow volume is a possible indication of bladder muscles which are not contracting appropriately. The uroflow machine, however, provides only an indirect indication of actual bladder function. The uroflow machine is unable, for instance, to distinguish between bladder dysfunction, i.e. incorrectly operating bladder muscles, and sphincter muscle dysfunction.
In contrast, the action of the bladder itself can be seen during the voiding process by using videofluoroscopy. X-rays illuminate the internal bladder, with the resulting image being cast on a fluorescent screen. Cystourethrography is another technique which uses X-rays to produce images of the bladder and urethra during voiding. The contrast of the various portions of the urinary system relative to surrounding tissue can be enhanced by various isotope-type drinks taken prior to the procedure. However, such X-ray type equipment is expensive and is sufficiently large that natural voiding is difficult. Also, the use of such equipment inherently involves potentially hazardous X-rays.
Ultrasound devices have been used in the past for diagnosis of various medical conditions, and are generally regarded as being both safe and effective. However, conventional ultrasound machines produce only two-dimensional images and are large enough to effectively prevent natural voiding. The ability of an apparatus to permit a patient to void in a natural manner is quite important for accurate diagnosis of actual bladder function, since the manner in which the patient voids can significantly affect the physical action of the bladder. In some postures, such as required by particular equipment, a patient may exercise more abdominal pressure than would be optimal for correct bladder function. On the other hand, if the patient must be supine, as would be the case for procedures using X-ray machines, the patient may apply less than optimal abdominal pressure, which could also produce inaccurate results.
Hence, it is desirable to have an apparatus which can be placed on the user which would not interfere with normal voiding action, yet be capable of producing accurate images of the actual bladder during the voiding process.
The present invention includes a system and method for continuously imaging a human bladder during voiding, comprising: generating successive images of a bladder during voiding, the images being sufficiently close in time to provide a sequence of images showing the bladder during voiding; controlling the operation of the ultrasound apparatus so that images of the bladder during voiding are captured; and processing said images to form a substantially continuous moving image, in the nature of a motion picture, during voiding, so that the functioning of the bladder during voiding can be directly observed.